Simulations of pixel moirés in the liquid crystal display with image processing technique

Abstract

The objective of this paper is to simulate the pixel moirés arising in the liquid crystal display with an image processing technique. The LCD panel and the backlight can be regarded as the micro shutter arrays and the surface illuminator, respectively. The RGB shutters have the spatial periodicity and the illumination lights condensed by a brightness enhancement film (BEF) also have the spatial periodicity depending on the prismatic structure size and orientation of a BEF. Pixel moirés become visible when the spatially aliased periods and amplitudes of illumination lights exceed certain critical values. Avoidance of pixel moirés in the liquid crystal display is a design problem related with choice of prism pitch and orientation of a BEF. In this study an image processing algorithm which can predict the pixel moirés arising in the liquid crystal display was devised, and prediction accuracy was investigated. As a design example, optimal values of prism pitch and orientation of a new BEF having relatively large pitches, 150–200 μm were tried to be found with a devised simulator, and simulation results were discussed.